Th1/Th2 cytokine polarization in three different anaesthesia protocols administered to cats undergoing ovariohysterectomy

This study investigated perioperative Th1/Th2 cytokine polarization and biochemical changes in cats undergoing ovariohysterectomy under three different anesthesia protocols. Twenty-four healthy mixed-breed female cats were randomly allocated into three groups (n = 8/group): propofol–isoflurane (Group I), xylazine–ketamine hydrochloride (Group II), and xylazine–isoflurane (Group III). Venous blood samples were collected preoperatively (0 h) and at 6 and 12 h postoperatively. Serum concentrations of TNF-α, IFN-γ, IL-2, IL-4, IL-5, and IL-10 were quantified using feline-specific ELISA kits, and biochemical variables were measured with an automated analyzer. In Group I, tumor necrosis factor (TNF)-α, increased postoperatively (12.64 ± 2.28 ng/mL) compared to preoperative levels (6.79 ± 0.74 ng/mL; p < 0.05). In Group II, both interferon (IFN)-γ and interleukin (IL)-2 levels decreased after the operation compared to pre-op 0 h (p < 0.05). Group III showed a decrease in IL-4 and IL-10 postoperatively (124.21 ± 23.45 pg/mL and 106.05 ± 5.25 ng/mL, respectively) compared to pre-op 0 h (197.28 ± 14.40 pg/mL and 113.14 ± 11.19 ng/mL, respectively; p < 0.05). IL-5 concentrations did not change significantly in any group. Postoperative biochemical changes were transient and remained within reference ranges, with no clinical complications observed. These findings indicate that anesthesia protocols differentially influence perioperative immune responses in cats. The xylazine–ketamine combination induced the greatest cytokine fluctuations, whereas xylazine–isoflurane best preserved Th1/Th2 balance. Anesthetic selection may play a critical role in minimizing perioperative immune modulation. The xylazine–isoflurane protocol may be a preferable option for feline ovariohysterectomy, particularly in patients where immune stability is clinically relevant. These findings indicate that anesthesia protocols are associated with distinct short-term perioperative immune profiles in cats undergoing elective ovariohysterectomy. The observed differences should be interpreted as preliminary and hypothesis-generating, and larger studies with standardized pain assessment and longer follow-up are warranted to clarify clinical implications.